PROJECTED TIMBER SUPPLIES 1970 LEVEL OF MANAGEMENT 



69 



T , m F =; fi Suvvlies of roundwood products per acre in the North, by owner class and species group, 1952, 



1 ABLt 00. 0< yy J ^^ ^ ^^ ^.^ p) . j ecti()ns fa 2Q20 





[Cubic feet] 













Owner class and species group 



1952 



1962 



1970 



Projections 



1980 



1990 



2000 



2020 



National Forests: 



2. 1 

 3.3 



2.5 

 4.3 



2.8 



4. 4 



5.5 

 9.4 



7.9 

 12. 2 



10. 3 

 15. 8 



10. 3 

 16.0 







5.4 



6.8 



7.2 



14.9 



20. 1 



26. 1 



26.3 



Other public : 



1.8 



3.3 



1. 9 

 4. 1 



2.3 

 4.4 



4. 3 

 10. 7 



6.2 

 15. 1 



8.0 

 19.8 



8. 1 

 19.9 







5. 1 



6.0 



6. 7 



15.0 



21. 3 



27.8 



28. 



Forest industry: 



9.8 

 9.4 



8. 7 

 8.3 



9.6 

 8.4 



11.7 

 10. 3 



13.8 

 12. 1 



16. 6 

 14. 3 



16. 6 



14. 3 







19.2 



17. 



18. 



22. 



25.9 



30.9 



30.9 



Farm and miscellaneous private : 



3.3 

 9.2 



2.5 

 8. 1 



2.6 

 8.7 



3.5 

 15. 1 



3.8 

 20.0 



4.2 

 24.4 



4. 2 

 24.8 







12.5 



3.5 



8. 1 



10.6 



11.3 



18.6 



23.8 



28.6 



29.0 



All owners: 



2.9 

 7.4 



3.3 

 7.9 



4. 5 

 13.8 



5.4 



18. 1 



6. 4 

 22. 2 



6. 5 

 22.4 







11.6 



10.3 



11.2 



18.3 



23.5 



28.6 



28.9 







with growing-stock trees. This mainly reflects 

 reductions in radial growth and increases in 

 mortality resulting from increased stocking in 

 younger stands, and the occupancy of much forest 

 land by rough and rotten trees or nontimber cover. 



Net annual growth rates as a percent of the 

 growing stock inventory averaged about 3.6 per- 

 cent in 1970. A moderate drop to an average of 2.6 

 percent by 2000 is estimated under the assump- 

 tions of this section, largely to the projected 

 buildup of both softwood and hardwood in- 

 ventories. 



Many of the differences in growth and in stand 

 conditions among ownership classes are the re- 

 sult of differences in forest types and levels of 

 management. Thus larger inventories per acre and 

 higher levels of growth on National Forests and 

 forest industry lands reflect in part higher pro- 

 portions of the more productive types such as 

 maple-birch-beech and spruce-fir. Farm and mis- 

 cellaneous private lands, on the other hand, 

 include relatively large proportions of the oak- 

 hickory type which generally occupies the drier 

 and less productive uplands. 



Proportions of stand-size classes in 1970 also 

 differed considerably by ownership. On public 



lands poletimber stands predominated, whereas 

 sawtimber stands were more important on forest 

 industry lands. 



Trends in Timber Inventories 



Because of the substantial surplus of net growth 

 over removals in recent years, volumes of growing 

 stock in the North increased about 42 percent 

 between 1952 and 1970 to an average of 875 cubic 

 feet per acre (table 58). Forest industry lands 

 and National Forests supported the heaviest 

 inventory volumes per acre in 1970, and such 

 differentials are projected to continue. For all 

 owners combined, the average inventory per acre 

 under the assumptions of this chapter is pro- 

 jected to increase a further 33 percent by 2020. 



PROJECTIONS OF TIMBER SUPPLIES IN THE 

 ROCKY MOUNTAINS 



The Rocky Mountain section contained 14.2 

 percent of the Nation's timber inventory in 1970 

 and accounted for 7.1 percent of the total national 

 output of roundwood products. Some 4 percent ot 

 the Nation's lumber and wood products establish- 

 ments were located in this area in 1967; these 



